Swimming speed

Range In a depolarizing solution of 4mM K+ (0.76±0.16mm/s) in standard solution 1mM K+ (0.99±0.26mm/s) mm/s
Organism Ciliate Paramecium caudatum
Reference Katsu-Kimura Y, Nakaya F, Baba SA, Mogami Y. Substantial energy expenditure for locomotion in ciliates verified by means of simultaneous measurement of oxygen consumption rate and swimming speed. J Exp Biol. 2009 Jun212(Pt 12):1819-24. doi: 10.1242/jeb.028894. p.1821 left column bottom paragraphPubMed ID19482999
Method "In this paper, [researchers] will present the energy expenditure of Paramecium in close relation to its swimming activity. For this purpose, paramecia were confined in a small volume of the chamber (<1 ml) and the oxygen consumption rate and the swimming speed were measured simultaneously from the same specimens. Oxygen consumption was measured by means of an optic fluorescence oxygen sensor (Okubo et al., 2008). Because this sensor has proved not to alter the amount of dissolved oxygen unlike oxygen electrodes, which consume a substantial amount of oxygen during the measurement procedure, it is ideal for measuring the oxygen concentration in a small volume of a sample. Swimming speed was measured from the recording obtained by the optical slice method (Kato et al., 2003)."
Comments "Paramecium has been known to reduce its swimming speed in response to the experimental depolarization of the membrane (Machemer, 1989). In the present study, [researchers] changed K+ concentration from 1mmol/l (standard solution) to 4mmol/l for this purpose. In a depolarizing solution of 4mmol/l K+, cells swam slower as expected (0.76±0.16mm/sec N=14 in this solution compared with 0.99±0.26mm/sec N=54 in the standard solution, P<0.01)."
Entered by Uri M
ID 110786